Vehicular tires, particularly pneumatic tires, are sometimes provided with a component, such as for example a tread, which is comprised of a rubber composition which contains particulate silica reinforcement, particularly synthetic amorphous precipitated silica.
The rubber composition of the component my also contain a silica coupling agent to aid in enhancing the reinforcing effect of the silica for the respective elastomer(s) of the rubber composition such as, for example, a tire tread.
Use of such precipitated silica reinforcement and associated coupling agent is well known to those having skill in such art.
A combination of various such hydroxyl functionalized elastomers and silica are variously disclosed in U.S. Pat. Nos. 4,150,014, 4,150,015, 4,152,308 and 4,357,432 and is therefore well known to those having skill in such art.
In the description of this invention, the terms “rubber” and “elastomer” if used herein, may be used interchangeably, unless otherwise prescribed. The terms “rubber composition”, “compounded rubber” and “rubber compound”, if used herein, are used interchangeably to refer to “rubber which has been blended or mixed with various ingredients and materials” and such terms are well known to those having skill in the rubber mixing or rubber compounding art.
The term “phr” where used herein, and according to conventional practice, refers to “parts of a respective material per 100 parts by weight of rubber, or elastomer”.
The Tg of an elastomer, if referred to herein, refers to a “glass transition temperature” of the elastomer which can conveniently be determined by a differential scanning calorimeter at a heating rate of 10° C. per minute.